Storage DRS on Thin LUNs without SCSI UNMAP

Good morning everyone.

I've been reading up on Storage DRS, and from my understanding the Storage DRS function will be using Storage VMotion to move the VM from LUN to LUN when/if needed. When doing so, it will also use the SCSI UNMAP feature for Storage Reclamation in vSphere 5 to make sure that the old diskspace is marked as free and can be used for new VMs. However, if an array supports Thin LUNs but not SCSI UNMAP, wouldn't that mean that if you use Storage DRS, the Thin LUN Pools would easily get filled up with stale and non-current data once the VMs start moving around?

My question is this: If I start using Storage DRS on my new fancy vSphere 5 environment, is there any version of EMCs VNX and VMAX lines that does support Storage DRS but not SCSI UNMAP? I just want to make sure that I won't have any issues when the VMs start moving around

Many thanks in advance,

Jonas